Time-resolved resonance Raman spectroscopy and density functional study of 2-fluorenylnitrene and its dehydroazepine products |
| |
Authors: | Ong Shing Yau Zhu Peizhi Poon Yuen Fan Leung King Hung Fang Wei-Hai Phillips David Lee |
| |
Institution: | Department of Chemistry, The University of Hong Kong Pokfulam Road, Hong Kong S.A.R., P. R. China. |
| |
Abstract: | We report time-resolved resonance Raman spectra for 2-fluorenylnitrene and its dehydroazepine products acquired after photolysis of 2-fluorenylnitrene in acetonitrile. The experimental Raman band frequencies exhibit good agreement with the calculated vibrational frequencies from UBPW91/cc-PVDZ density functional calculations for the singlet and triplet states of the 2-fluorenylnitrene as well as BPW91/cc-PVDZ calculations for the two dehydroazepine ring-expansion product species. The decay of the 2-fluorenylnitrene Raman signal and the appearance of the dehydroazepine products suggest the presence of an intermediate species (probably an azirine) that does not absorb very much at the 416 nm probe wavelength used in the time-resolved resonance Raman experiments. Comparison of the singlet 2-fluorenylnitrene species with the singlet 2-fluorenylnitrenium ion species indicates that protonation of the nitrene to give the nitrenium ion leads to a significant enhancement of the cyclohexadienyl character of the phenyl rings without much change of the C-N bond length. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |